Caster.



' PATENTED JAN. 29, 1907.

m m w H n H M a W v APPLICATION FILED SEPT. 25, 1905.

y d U arwenfoz 1 UNITED s'rATEs OFFICE.

RICHARD E. BIERD, OF SEATTLE, .wAsHINGToN I .GASTERQ SpecificationofLetters Patent;

hpplication'filed se t'ma 25,1905. Seria1.No-280,064'.' 1

exact description of the invention, such as will enable others skilledin the art to which it appertains to make and use the same.

This invention relates to improvements in casters, and has particularreference to ball bearing casters, in which the ball-bearing cannot haveany other than a rollin fi'iction upon the balls and theirguiding-smiace'st The object of this invention is to provide acasterwhich is adapted to be attached to ob eds, &c., and, furthermore,to produce an ab.- solutely frictionless caster both in the run ning aswell as in the swiveling of the same; i

With these and other objects in view my invention consists in suchfurther features and details which will be described in connection' withthe accompanying drawings and more particularly pointed out in theclaim.

.Inthe drawings, Figure 1 is a view or the improved caster in sideelevation with theattaching-plate in diametrical section. Fig.2; is avertical sectional view taken on line 2 2 of Fig. 1.- Fig. 3 is a viewin side elevation of the arms and associated disks. Fig.- 4 is a view invertical section of the ball-spacer.

The casterl'forming' the subject-matter of this application comprisesashank 1,with any approved fastening means, as the platev 2,

rigidly associated v therewith, and with its plane substantially atright angles to the axis of the shank. 5 The under side of the plate 2'is provided with a downwardly and inwardly extending boss or annularflange 3, internally cupped, witha lower and inwardlyrextending ed e orlip 4,.forming theouter portion of the b'a l-race for the accommodationof the bearin -balls 5. l

ithin the recess formed by the boss is disposed a cap 6, having aperipherallateral ects of the heavy type, such as tables, pianos,

. disk. and cap, di

of the arm structure and defining the cavity 8,

. within which is seated the rivet 25 for. holding to ether'the parts 6and 7. Upon the disk-1i e portion 7 a shoulder 9 is formed carrying thearms I10,'preferably formed at their lower ends with disks 10proportioned to be secured ri 'dly together by means of the rivet 24central y of the said disk-like portion and defining a groove 24;,forming a ball -"race entirely about the external periphery of thecurveproportioned'to form a portion of the ballrace to coo erate with asimilarlyformed portion 9, ormed upon the upper end Patented gun.29.1907.-

said combined disks. About and encircling the said diskslOis the rim 20,formed with a groove 21 in its inner periphery proportionedtocooperatewith thegroove 24 tofo'rm a race in which are disposedbearing-balls- 22,.

circling the disks 10, I

What I claimis V In acasterp'an attaching-plate provided with adepending inturned flange formin'gba ballrace,- arms 'oined at theirupper ends y positioned in openingsof the spacer 23, ,en-'

a disk provide 'with-a peri heral groove, a

cap rigidl connected with t n e disk and provided wit a cooperatingoo've, the said cap and disk being dlsposed Within the depending flangeof the plate, balls disposed withinthe ball-race of the plsate and thegroove of the with outturned flanges defining a all-race, means rigidlyconnecting the disks ,a run en circling the connected disks and rovidedwith a roove about its inner perip ery core 'respon 'n the joined Itween the eripheries of the disk and the T1111,

and coact-ing with the groove of and spaced by the spacer;

In testimony whereof I affix my signature in presence of two witnesses.RICHARD E. BIERD.

Witnesses:

G. WARD KEMP, MARK 'WHELAN.

disks, a ball-spacer disposed be-' formed upon and integral with thelower ends of the arms and rovided 8 and balls isposed between the rimand disks

